What is the ideal free chlorine level for a swimming pool?
Regardless of how frequently or what system you use to add chlorine to the water, the chlorine level should stay between 1.0 and 3.0 parts per million (ppm) to maintain a healthy pool. Any higher and you start to run the risk of red eyes and swimmers itch.
Free chlorine refers to both hypochlorous acid (HOCl) and the hypochlorite (OCl-) ion or bleach, and is commonly added to water systems for disinfection. Chloramines are also known as combined chlorine. Total chlorine is the sum of free chlorine and combined chlorine.
- A great product for swimming pool maintenance. For outdoor swimming pools. Reduces chlorine loss caused by the sun's ultraviolet rays. Adding stabilizer in the spring greatly increases chlorine effectiveness and can actually cut chlorine consumption by up to 25% a year.
- Related to pH, total alkalinity is a measure of the alkaline substances in the water. The pH depends on TA. When maintained at proper levels, pool water resists a change in pH. Hardness, on the other hand, is a measure of the calcium and magnesium in the water.
- Fi-Clor Non-Chlorine Shock can be used to shock dose pools which use all types of chlorine as a sanitiser without boosting chlorine levels. It may also be used for reactivating spent Bromine in Bromine treated pools. It is an ideal shock treatment for pools using automatic pool covers.
Should I swim in a pool with a “low” free chlorine level? Free chlorine is the most important number to monitor in your swimming pool water. You want it between 1.0-3.0 ppm. Free chlorine keeps the water clean and safe from harmful bacteria.
- Even if the water is not completely clear, but more of a cloudy blue-ish color, you could allow limited swimming. And if you have recently shocked the pool with granular chlorine, follow the label instructions about when it's safe to swim. Undissolved granules could irritate the eyes and skin of swimmers.
- Commercial pools should run their chlorine levels at 3 -5 ppm as their bather load is usually much higher. Anything between 5-10 ppm is still safe to swim, but you are risking damage to equipment and certainly complaints from swimmers. Some experts recommend no swimming unless the chlorine is 8 ppm or less.
- It is recommended to wait at least 20 minutes to an hour after adding water balancing chemicals. You should wait 2-4 hours (or one full cycle through the filter) to swim from the moment you use calcium chloride in your pool. It is safe to swim once your chlorine levels are around 5 ppm or after 24 hours.
Updated: 18th November 2019